1. Field of the Invention
The present invention relates to an information processing device that includes a first information processing unit including a communication unit for communicating with an external device; and a second information processing unit that is connected to the first information processing unit through a data communication line.
2. Description of the Related Art
In order to address a demand for reduction in power consumption, an information processing device can be divided into a plurality of power source domains. During the power saving mode in which the power consumption is reduced, a power control circuit reduces the power consumption by turning off power supplies other than power supplies for power source domains that correspond to predetermined necessary functions.
For example, a designer may define a communication function to be a single power source domain, and the designer can design the communication function as a subsystem. The designer may adopt a design such that, during a power saving mode, electric power is supplied only to the subsystem. A main system may be defined to be another power source domain. The main system may include, for example, a central processing unit (CPU). During the power saving mode, electric power is not supplied to the main system. As a consequence, during the power saving mode, the information processing device can reduce the power consumption, while performing communication.
Not only during the power saving mode, but also when power is supplied to the main system, the subsystem takes charge of communication of data that is used for an application operating in the main system. However, memory capacity and the like of the subsystem may be less than that of the main system. Namely, an amount of communication resources (e.g., a buffer) of the subsystem may be less than that of the main system or that of a server of a communication destination. The subsystem may only exchange a small amount of data during a single transmission and reception process. Consequently, supply of data to the application of the main system may be delayed. As described, in a system in which a subsystem and a main system are divided, and the subsystem takes charge of communication, the subsystem may be a bottleneck of the communication.
To overcome such a disadvantage, a size of a buffer to be allocated to a communication process may be varied (cf. Patent Document 1 (Japanese Patent No. 3761317), for example).